Orwin, K.H., Kirschbaum, M.U.F., St. John, M.G., Dickie, I.A. (2011). Organic nutrient uptake by mycorrhizal fungi enhances ecosystem carbon storage: a model-based assessment. Ecology Letters 14: 493-502.
Abstract. Understanding
the factors that drive soil carbon (C) accumulation is of fundamental importance
given their potential to mitigate climate change. Much research has focused on
the relationship between plant traits and C sequestration, but no studies to
date have quantitatively considered traits of their mycorrhizal symbionts.Here,
we use a modelling approach to assess the contribution of an important
mycorrhizal fungal trait, organic nutrient uptake, to soil C accumulation. We
show that organic nutrient uptake can significantly increase soil C storage, and
that it has a greater effect under nutrient-limited conditions. The main
mechanism behind this was an increase in plant C fixation and subsequent
increased C inputs to soil through mycorrhizal fungi. Reduced decomposition due
to increased nutrient limitation of saprotrophs also played a role. Our results
indicate that direct uptake of nutrients from organic pools by mycorrhizal fungi
could have a significant effect on ecosystem
C cycling and storage.
Keywords: Ectomycorrhizas, ericoid mycorrhizas, microbial nutrient
limitation, model, mycorrhizal traits, MySCaN, organic nutrient uptake, soil
carbon storage.